list_credentials

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Without annotations, the description clarifies the return: a list of VCs matching the subject DID, or empty if none. This discloses the behavioral outcome. It does not mention side effects or auth needs, but since this is a read-only list, the description is sufficiently transparent.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is concise: two sentences for purpose and parameter, plus a note on return. No unnecessary words, and the main action is front-loaded.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the tool's simplicity (single parameter, list output), the description covers what it does, parameter explanation, and return value. It is complete for an agent to use correctly without additional context.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 0%, so the description adds critical meaning: subject is the 'subject DID (credentialSubject.id)'. This clarifies the parameter semantic beyond the schema's bare type definition.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states 'List all Verifiable Credentials issued to a subject DID', specifying the action (list), resource (VCs), and scope (by subject). It distinguishes from sibling tools like get_vc or resolve_vc by focusing on listing multiple credentials for a given subject.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description implies usage for listing VCs of a specific subject but does not explicitly mention when to use vs. alternatives (e.g., get_vc for a single VC). No exclusions or alternative conditions are provided.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.